main.cpp

#include <stdio.h>
#include <iostream>
#include "quantum.hpp"

using namespace std;


void oracle(qureg& r) {
	const uint32_t test_for = 5;
	
	//apply function
	for (int i = 0; i < 4; i++) r.op_X(2*i+1);
	r.gate(qugate::increment(123, 8), bit_range(0, 7));
	
	//do a conditional Z gate by turning |test_for> to |11...1>
	for (int i = 0; i < 8; i++)
		if (!(test_for & (1 << i))) r.op_X(i);
	r.op_X(8);
	r.gate(qugate::pauli_Z(), {8}, bit_range(0, 7));
	r.op_X(8);
	for (int i = 0; i < 8; i++)
		if (!(test_for & (1 << i))) r.op_X(i);
	
	//apply reversal of function, resetting ancilla bits
	r.gate(qugate::increment(-123, 8), bit_range(0, 7));
	for (int i = 0; i < 4; i++) r.op_X(2*i+1);
}

void grover(qureg& r) {
	const int it = round(M_PI * 0.25 * sqrt(1 << 8));
	
	r.op_hadamard_range(0, 7);
	for (int i = 0; i < it; i++) {
		//apply oracle
		oracle(r);
		
		//grover diffusion
		r.op_hadamard_range(0, 7);
		r.op_X_range(0, 8);
		r.gate(qugate::pauli_Z(), {8}, bit_range(0, 7));
		r.op_X_range(0, 8);
		r.op_hadamard_range(0, 7);
	}
}

int main(void) {
	qureg r(9, 0);
	
	grover(r);
	
	cout << r.state << endl;
	
	uint64_t x;
	printf("measured: %lu\n", x = r.measure());
	cout << print_bits(x, 6) << endl;
	cout << "probability: " << r.probability(x) << endl;
	
	return 0;
}